<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="./lib/react.development.js"></script>
    <script src="./lib/react-dom.development.js"></script>
    <script src="./lib/babel.min.js"></script>
    <style>
        .bg{
            background: red;
        }
        .cl{
            color:green;
        }
    </style>
</head>
<body>
<div id="root">

</div>

</body>
<script type="text/babel">
    // js class
    const root = ReactDOM.createRoot(document.querySelector("#root"));
    const abc = "bg cl";
    root.render((
        <div>
            <p className={"bg cl"}>我现在正在好好学习，天天向上</p>
            <p className="bg cl">我现在正在好好学习，天天向上</p>
            <p className={abc}>我现在正在好好学习，天天向上</p>
        </div>
    ));
</script>
</html>